Harry Potter and the Eighth Chevron
by justanothermuggle
Summary: This story is a sequel to my HP/SG-1 crossover Harry Potter and the Chappa'ai. Following the defeat of Anubis SG-1 and their wizading friends are called to assist Atlantis to fight off a Wraith attack.
1. Prologue

_A/N I've received several reviews asking me to write a sequel for Harry Potter and the Chappa'ai. I haven't done so earlier because I had no plot for a sequel. But a few days ago I was chatting with my friend ghost chicken, and we came up with a plot._

_Since this is a crossover I don't follow canon strictly, so any deviation from canon is most likely deliberate. The SG-1 time line isn't canonical. This story takes place in 1998 and loosely corresponds with the end of the first season of Stargate Atlantis. For HP it's the summer following the end of Harry Potter and the Deathly Hallows._

_Finally: Harry Potter is JKRs yard, and everything Stargate belongs to MGM. I'm only here to play._

_I hope you'll enjoy this story. I recommend reading Harry Potter and the Chappa'ai before reading this one._

**Harry Potter and the Eighth Chevron**

**Prologue**

Jack O'Neill had loaded his video recorder with Simpsons and was just about to open a long overdue beer when the phone rang. He sighed, seeing the number, and answered.  
"For crying out loud, we just threw the goa'uld into a civil war, whooped Anubis out of our existence. What now?"  
"Sorry sir." Harriman said. "The general asked you to come to the SGC immediately. With SG-M."  
Jack sighed. Not even a day after Anubis' defeat and there was something new.  
"We'll be there..." Jack sighed and returned the beer to the fridge.

Jack called Sam and asked her to gather SG-1 while he took a trip to England to gather SG-M.

***

An hour later Jack entered the briefing room at SGC followed by Harry, Ron Hermione and Gawain. In the briefing room were Teal'c, Sam and Daniel already seated. General Hammond was waiting for them, inviting them to sit down. As soon as they were seated the general looked at them with a concerned face.

"About an hour ago we had a communication from the Atlantis expedition." General Hammond declared "They reported that they're under attack from a Wraith hive ship. Shields are holding for now, but they need help."

"Atlantis?" Hermione asked, since she was aware of Plato's legend about the Lost City.

"Wraith?" Ron asked.

"Atlantis is a city where the Ancients used to live." Daniel interjected.

"And the Wraith are some nasty life sucking aliens." Jack added.

"Life sucking?" Harry asked.

"Lacking exact knowledge about their feeding it's a viable description." General Hammond told them.

"They suck you dry, and you end up looking like those mummies we ran into in Egypt, only dead, not undead and very inanimate." Jack added.

"But right now we need to come up with a plan on assisting Atlantis." general Hammond interrupted.

"Since we know wizards and witches are related to the Ancients and that their magic is linked to zero-point energy, maybe SG-M would be able to reinforce the city shields." Sam suggested.

Ron looked doubtfully at her.

"We're not good at anything sceptological." he explained.

"Technological." Hermione whispered in his ear.

"Did you say city shields?" Gawain asked.

"Yes, Atlantis is protected by a powerful shield, which also has the potential to cloak the city." Sam said.

"That sounds a lot more like Ministry controlled magic, than the kind we cast as individuals." Hermione concluded.

Gawain nodded in agreement.

"Would this ministry controlled magic work in another galaxy?" General Hammond asked.

"The magical powers of the Ministry are imbued in the Ministry building itself, and through hard training there are those who handle and monitor the Floo network, charms like the Trace, or the magic that hides public wizarding areas such as Platform 9 ¾ or Diagon Alley from Muggles. In other powerful magical places like Hogwarts School of Witchcraft and Wizardry that power lies with the current Headmaster or Headmistress."

"All right. That kind of magic is certainly what we need here." general Hammond realised "SG-M your job is to get the wizard or witch that can handle this, and provide protection until the Wraith attack is fought off."

"I think we need to return to the Ministry and bring in someone with more insight in the Ministry controlled magic." Gawain said.

"All right." general Hammond replied.

"There's one more thing." Gawain added.

"What?" Jack asked.

"This will only work if the necessary magical power is imbued and available in Atlantis." Gawain said.

"And we won't know that until we arrive?" Jack asked for clarification.

Gawain nodded.

"So there's a chance we all go to Atlantis only to find that there's little you magical people can do other than giving the Wraith one helluva fight." general Hammond concluded,

SG-M nodded.

"Good, I'd hate if that'd come as a surprise once we're there." Jack said.

"I can always offer you an AK as an option to being sucked dry by a Wraith." Gawain said politely.

"Given the choice, thank you, but I have a six pack and Simpsons waiting for me when I get back home." Jack replied "Which I intend to do."

"Enough already." general Hammond said "You have your tasks. You have a go for a rescue mission as soon as SG-M returns."

On their way back to the Ministry they all talked about who they could bring along.

"Of course Kingsley would jump at the chance, and he'd be ideal, since he's a former Auror, can handle a fight, and has access to the full power of the Ministry since he became Minister for Magic." Gawain said.

"But?" Harry asked.

"As Minister for Magic he's not allowed to risk his life by participating in planned operations involving lethal duels." Hermione said.

"Would Percy do?" Ron asked.

"Are you mental?" Harry said.

Gawain looked thoughtfully on Ron.

"Actually that's not a bad idea. He's on the Minister's staff doing... something. That means Kingsley can give him access to most of the Ministry controlled magic." Gawain reasoned.

"And since we know the Ministry dates back to Merlin, who was an Ancient, it's likely that any magic imbued in Atlantis will be available to a current official of the Ministry Merlin founded." Hermione suggested.

Gawain nodded.

"I think that's our best shot." he agreed.

Upon arrival at the Ministry they asked for an immediate meeting with Kingsley and Percy. They updated Kingsley and broke the news of their cooperation with American Muggle Military to Percy. Finally they offered their suggestion to include Percy on the team. Kingsley looked worried.

"I really wish that we had time to research this, but with the battle going on as we speak I think this is out best chance." Kingsley concluded "Percy, are you willing to join the team?"

"Well, yes. I think so." Percy said looking rather nervous.

"You'll do just fine brother." Ron said "You fought at Hogwarts. And this time you'll have us and the Muggles protecting you."

Percy seemed to relax hearing Ron's approval. He was still feeling awkward after being reunited with his family.

"All right. I'm in." Percy declared.

Kingsley nodded and performed a series of complicated wand work, muttering a long incantation. After a faint glow around Percy Kingsley tucked his wand into his robes.

"Percy, I have given you access to all Ministry controlled magic I'm capable of. Hopefully that will help you to find and access what we seek in Atlantis. Good luck to all of you."

The group of five left the Ministry, in order to apparate to their transportation site.

"So this is what you've been up to?" Percy asked "Working with Muggle Military, American Military."

"Yes Percy. We've learned new things about Merlin and about what magic really is. Given time we might be able to develop a defence against the Killing curse and a whole range of new spells." Hermione said.

"Amazing." Percy commented.

"We're about to be transported." Gawain told them.

In a flash of light they vanished from Britain, bounced through the transporter on the Prometheus and reappeared in the SGC. General Hammond awaited them.

"That was impressive." Percy agreed, realising his Dad's fascination with Muggles wasn't unfounded.

"Welcome to Colorado, USA, and Stargate Command." general Hammond greeted him "I'm general Hammond, commander of this base."

Percy looked around.

"USA? We're in USA?" he asked.

"Yes Percy, their apparation technology is very practical." Hermione explained.

Percy, still a bit overwhelmed, turned to the general.

"Percy Weasley, junior secretary on the Minister for Magic's staff." he introduced himself.

"Weasley?" general Hammond asked.

"Yes, he's my brother." Ron confirmed "And he has all the power Kingsley could give him."

"If you're ready, SG-1 is waiting for you in the gate room."

SG-M and Percy headed down the stair from the briefing room and entered the gate room. SG-1 were geared up in full battle outfit, Teal'c looking intimidating with his staff weapon and Jack confidently holding his P-90.

"Mates, meet Percy Weasley, my brother." Ron said."

"Whackiness must run in your family Ron." Jack grinned "Your brother Bill helped us in Egypt, and now Percy here will join us for this mission, and quite frankly one has to be a bit whacko to do what we do."

Teal'c raised an eyebrow.

"Indeed."

"Don't mind them." Harry told Percy "It's just part of Jack's charm."

Percy nodded, looking a bit disappointed that the Muggle Military so far seemed rather informal. He'd expected strictness, formality and organisation, traits he truly appreciated. But thinking about it, their Auror Office, the very elite fighters, were all a bit _whacko_ too. _Must be a way to handle battle stress, right? _The introductions were made short and simple since they needed to be on their way.

"General" Jack said "We are ready to leave for a rescue mission to Atlantis."

"You have go colonel" general Hammond replied and turned to Sgt Harriman "Walter, dial Atlantis."

Moments later the Stargate began spinning, causing Percy to look at it with great interest.

"Just wait until it connects, that is really impressive." Sam said "But unlike gate travel within the Milky Way we need to add an eighth chevron."

Percy nodded, despite he had no idea what Sam was talking about. Hermione noted this.

"This Stargate is like a galactic Floo network." she explained "And normally we only have to toss some Floo powder into the Floo and state out destination, but if you'd like to Floo to France, you'd have to set up an international Floo connection."

"Of course." Percy said.

"The Stargate uses symbols instead of Floo powder, and normally there are seven of them, but in this case we're setting up an international call, well, intergalactic to be specific, and that means they add an eighth symbol."

"I understand."

"Chevron eight, locked" Sgt Harriman called out on the speaker and the Stargate connected.

Percy jumped backwards from the vortex forming, but calmed down when it settled.

"This is colonel Jack O'Neill calling Atlantis. We're ready to come through. What's your status?"

The radio crackled for a moment before the reply came.

"We're holding the gate room and Central tower, but there's been glitches in the shield and the Wraith has punched through. There's man to man combat all over the city." Dr Weir's voice told them.

"Dr Weir, stand by, we're coming though." Jack responded.

"You're all clear." she replied "I'll inform Sheppard and have his team meet up with you."

"Thank you. SG-1 out." Jack finished and turned to the others "I'll go first with Teal'c. SG-M follows. Sam and Daniel covers our six. I'm not taking any chances. Lock and load, wands out."

As ordered they moved out and stepped though the Stargate.

"Breathe out before you step though Percy." Ron suggested.

"Just like a Floo, right?" Percy asked with a tremble in his voice.

Ron gave his brother a friendly push though the event horizon.

"Well, not exactly like a Floo, but he'll just have to see that for himself." Ron shrugged and stepped though.

Hermione shook her head before she too entered the event horizon. With Sam and Daniel through the wormhole disconnected.

***

Lieutenant colonel John Shepperd led his team back towards the gate room. Dr Weir had notified him about reinforcements from Stargate Command.

"And it's about time they arrive." John told himself.

Teyla and Rodney were following him and it was with great relief they entered the gate room. It was, however, rather discouraging to see only nine people, even if four of them were SG-1.

"Where's the rest of the army?" John asked while they approached the newly arrived people.

"We're it John." Jack said.

"Hey, don't think I'm unappreciative here." John said "But we're facing an entire hive here, pounding us with all they've got and with thousands of Wraith just waiting to get their hands on us in the very literal sense and on this city in the more figurative sense."

"Did you pass by the kindergarten on the way here?" Rodney asked noticing the teenagers in the group.

Sam sighed and turned to Hermione with a low voice.

"Rodney McKay, brilliant guy, but don't tell him I said that, arrogant and totally unaware of your talents."

Jack looked at SG-M and then at Rodney.

"Rodney, charming as always. They're here to save your butt." Jack said.

"Ha, ha." Rodney said with a bored tone.

Jack sighed. There was no time to win the trust of the stubborn Canadian, so the alternative was to shock him. Jack turned to SG-M.

"Could either of you please demonstrate on Dr McKay here exactly why you're the ones who'll save his butt? Jack asked politely "But we need him in original and unharmed shape after the demonstration."

Sam quickly whispered something in Hermione's ear.

"All right." Hermione said and drew her wand and flicked it.

Where Rodney had been standing the moment before was a warthog. Hermione cast an Imperius on the hog and made it purr like a kitten and stroke itself against the legs of Shepperd and Teyla. Shepperd looked in shock at the hog.

"Is that Rodney?" he asked.

Hermione nodded.

"What exactly are you folks?"

Jack grinned.

"This, John, is SG-M a team of three British wizards Harry, Ron and Gawain and an equally British witch, Hermione. They're some kind of modern day Ancients living in secret. We ran into them a few weeks ago and they have already helped us defeat Anubis. We also have Percy, high Ministry official."

There was a hint of pride in Percy's eyes as he heard Jack's introduction.

"All right, anything Ancient-related is very welcome." John said and looked at the warthog by his feet "You better turn Rodney back or I might get used to this and prefer him in this form."

With a flick of Hermione's wand the warthog turned back into Rodney who glared at John.

"I heard that Shepperd." he huffed and got up.

Dr Weir decided that they needed to focus at the job at hand.

"What's the plan then?" she asked.

Gawain and Percy quickly explained the plan.

"It seems to be a sound plan, but what do we need to do?" John asked.

"Let me think about how I can explain it." Percy said "You have those Muggle confusers, right?"

The Atlantis team members looked puzzled.

"Computers." Hermione clarified "All-wizarding people often have trouble pronouncing Muggle words, and Muggles are non-magical people."

"Yes, we have computers." Rodney replied, clearly convinced that SG-M would be helpful after his temporary transfiguration into a warthog, since he didn't even seem to think less of them for getting the word wrong.

"And they're access points, from where you control this city?" Percy asked.

"Yes." Rodney confirmed.

"Well, I need to find a magical access point, where I can control the magical core we hope is imbued in the city."

"And if that works?" John asked.

"I'll do what I can to use that power to apparate all Wraiths off the city and strengthen the shield magically."

They all nodded approvingly. This seemed like the best shot they had.

"What do you need?" Dr Weir asked.

"I need someone who knows the city." Percy said "And of course some people to protect me. When I access the magical core I won't be able to do anything but working on the defence of the city."

Dr Weir looked at John.

"You and Teyla go with him. The rest of you can work in a perimeter, clearing the surrounding areas."

"I'll join Percy too. I'm a Ministry employee and in case Percy needs a second opinion about how to handle the magic in the city I'm the best suited for that." Gawain said.

Percy nodded and Dr Weir looked at Rodney.

"I want you along with Sam here to monitor any changes in the systems." she ordered.

"Harry and Daniel with me" Jack said "Teal'c, Ron and Hermione, you're the second perimeter team."

With the plan finalized the three teams moved out.

"Be prepared for anything" John advised "All power is rerouted to shields, so we can't be sure life sign detectors are working. Where do you want to go Percy?"

Percy thought about the question for a few moments.

"Some kind of power central would be a good start. In the Ministry all those things are deep within the building in the Department of Mysteries. Your gate room is like the Atrium."

"That'd mean we're going all the way down in the Central tower to the Main Power Room." John said.

"If Merlin constructed the Ministry based on this city that would be a good place to start." Percy said.

Slowly they moved down the floors without opposition.

"If we're lucky the Wraith haven't penetrated the Central tower yet." Teyla said.

"I doubt this'll work without some kind of hitch." John mumbled.

To his surprise they reached the Main Power Room safely. John reported the progress on his radio and Percy drew his wand and started to examine the room.

"If there's magic there are traces of it. I only need to find it, in order to see how I access any imbued magic." Percy said while he cast a series of examination spells in the room.

"Heads up folk. We have a Wraith here" Jack's voice reported before it was drowned in gun fire.

"Teyla, guard the door. I'll be in the corridor." John said.

Jack fired his P-90 and it took the better part of his magazine to snuff the Wraith. As he reloaded two more entered the corridor. Harry took aim, eager to see how magic worked against the Wraith.

"Stupefy" he yelled and a red beam shot out of his wand.

It hit the Wraith in the chest and it collapsed, clearly in pain, but the stunner only seemed to knock the wind out of a Wraith.

"Um Harry." Daniel said a bit worried, but he realised Harry needed to find out what spells would work.

"Confringo" Harry yelled, shooting off a beam toward the second Wraith.

Harrys blasting curse hit the Wraith in the hip and killed it immediately as the explosion ripped it apart. By now the first Wraith was on its feet again.

"Avada Kedavra" Harry hissed.

Harry didn't like using the Killing curse, but this was war and a new species. They needed to know what spells were effective and this particular Wraith would be killed anyway. The green jet hit its target and it worked flawlessly. The Wraith fell limp to the floor.

"Good work Harry." Jack said "The Wraith are resilient bastards, but your spells seems to do the trick."

"I tried to stun it. That didn't work at all. But the blasting and the killing curse were effective."

Daniel looked at the two dead bodies on the floor, and the charred remains of the third one spread across the corridor.

"Killing curse from now on, right? That blasting curse will be a mess to clean up."

"It's just that the AK is so horrible and it's Dark Magic. I prefer to use it only when necessary. Against Anubis warriors there was no other option, but against the Wraith there is." Harry explained "In Wizarding Britain you get a life sentence in Azkaban if you use the AK."

Jack urged them forward to find any other stray Wraith.

Hermione, Ron and Teal'c were on the opposite side of the Central Tower, from Jack's position. They moved more cautiously now that they knew there were Wraith inside the Central tower. Harry had reported the spells he'd fired and the result. A sudden explosion made the three take cover. It was one of the gates from a walkway to the next tower that was blown. Dozens of Wraith were advancing into the tower.

"There's no stopping all of them, just the three of us." Teal'c said.

"We need to regroup with Jack's team and defend Percy's position." Ron suggested.

"Indeed." Teal'c agreed.

Hermione made a report on the radio and both teams moved towards the Main Power Room. When they arrived Percy was still examining the room.

"How's it coming Perce?" Ron asked.

"I'm getting there." Percy replied "There's magic here, but I need to get hold of it. But I'm getting closer."

They all drew a sigh in relief. There was hope after all.

"No pressure, but there's a lot of Wraith coming this way." Jack enlightened him.

"And one error by me and the magic might backfire. Wraith would be the least of your troubles it that happens." Percy replied.

Jack looked at Hermione.

"He's right." she said.

John alerted them.

"Wraith coming this way."

John, Jack Gawain and Ron left to fight them off and met them in the end of a corridor. The fight started immediately.

"If we could shut this door we'd win some time." John said and nodded to Ron "Press that button"

Ron pressed it but nothing happened.

"That's bad." John said firing his gun.

"The panel on the other side is lit." Gawain noted. "Ron, cast a shield for me, and I'll press the button and close the door before I apparate back into this corridor."

Gawain slipped though the doorway, and Ron's shield was hit by several Wraith blasts. Gawain shut the door.

"I hope Gawain blasts the panel before he gets out of there." John said.

"Of course he will." Ron said.

A few moments passed before the closed door was attacked.

"Gawain, where are you?" Ron asked himself.

In the Main Power Room Percy made progress. He accessed the imbued magic and found an several inactive charms.

"I think one of them is an Anti-Wraith charm and there's a shield charm." Percy said.

"Can you activate them?" Harry asked.

Percy moved his wand slowly. Reading residual magic wasn't like reading a book. It was hints and notions rather than a specific instruction. In the end it came down to Percy's gut feeling about the charms he identified.

"Yes, but I can't guarantee it'll work, or won't harm us." Percy said.

"We have Wraith in the Central Tower. We don't have much choice. Do it." Harry told him.

Percy flicked his wand and activated what he thought was the Anti-Wraith charm, followed by the shield charm. Harry reported to Jack. In the corridor outside Jack reached for his radio.

"Rodney, anything at your end?" Jack asked.

There was a brief silence.

"Amazing! Shields are at full power. Sensors are restored. Hold on." Rodney reported "All Wraith life signs are gone. Sam?"

"Sir, the hive is powering up. It'll go to hyperspace in a minute. They're withdrawing."

Ron apparated to the other side of the closed door the moment he heard that the Wraith were gone. Gawain was nowhere to be seen.

"Bloody hell. Where is he?"

Ron apparated back to join his team. If front of him, Jack and John appeared Gawain's Patronus.

"I'm on the hive ship. I'm locked up, so I don't think they intend to suck me dry just yet. I still have my wand, so I'll try to get out of here." the Patronus reported before dissolving in a silvery mist.

"The bastards took him." John grunted.

The radio cracked again and Dr Weir's voice called out.

"The hive is gone into hyperspace." she said "We made it. Thank you."

Gathered in the briefing room everyone gave their report. Rodney started.

"After Percy activated the shield the ZPM began recharging. It'll be fully restored tomorrow. We'll be able to dial earth, raise the cloak or the shield at full strength for a long time."

"I'd recommend a couple of Unspeakables to be sent here to research the magic." Percy added.

"Thank you." Dr Weir said and turned to John.

"We lost Gawain. He sent a message from the hive. He was imprisoned, but still had his wand." John said "Gawain saved us by closing that door. If the Wraith would have advanced further they'd reached the Main Power Room. Sam, anything on that hive?"

"We don't know where they headed." she said sadly.

"Anything else we need to know?" Dr Weir asked.

Harry nodded.

"The Wraith weren't knocked out by a stunner, but the Killing curse worked, and the blasting curse." he said.

"And a shield charm stops their weapons." Ron added.

Dr Weir looked at each one of them as she thought about how to proceed.

"I'd appreciate help from the Unspeakables. Any means that will strengthen the defence of this city is worth pursuing." she said "As for Gawain Robards. We must assume he's still alive. We'll alert our friends around the galaxy. When we know where the hive is, we'll stage a rescue attempt. Until then I suggest SG-1 and SG-M returns to earth tomorrow after the ZPM is fully charged. When Gawain is located we'll request your assistance to bring him home."

***

_**Three months later...**_

In an uninhabited solar system in the Pegasus galaxy two hive ships appeared from hyperspace. The commander on the bigger one of the two hives smiled as he saw the other approach.

"Why are we summoned here?" the other commander's voice was heard.

"We are here to offer you a chance to join us." the commander replied "You are outmanned and outgunned."

"Are you threatening me?"

"I'm stating the facts."

For a few moments nothing happened, but then the smaller ship started to move away as it covered its retreat with a full volley from all weapons.

"Evasive action." the commander ordered "Fire the main weapon."

He waited for his last order to be executed with a some trepidation, but mostly excitement. He had had lost a battle against the humans three months earlier, but that mission hadn't been a complete waste. He looked on the screen as the main weapon fired. It was a sickly green beam that hit the enemy hive.

"Report." the commander demanded.

The Wraith at sensors looked at them totally flabbergasted.

"Sir, I'm not sure these readings are correct."

"What does your sensors say?" the commander asked.

"There's no neural activity in the enemy hive's systems. And what's more, there are no life signs at all."

The commander nodded with a smile. He may had lost the battle of Atlantis, but he thought he'd just won the Pegasus galaxy.


	2. Chapter 1 Discoveries

**Chapter 1 - Discoveries**

It was late in September and it had been three months since Gawain had been lost in the Pegasus galaxy. Based on the reports posted after the mission and the hearing at the Ministry Kingsley had concluded that Gawain's actions could be considered somewhat reckless, but given the situation no one had opted for a reprimand and no one blamed the other team members. Harry, Ron and Hermione still felt there should've been something more they could've done to save Gawain. Now it was September and there'd been no news from Atlantis. Harry had spent most of the summer at the Burrow with Ginny, and with Ron and Hermione of course. The summer months had done miracles for their relationships and coming to terms with their war experiences. All four had received a Hogwarts letter inviting them to the seventh year. Ginny and Hermione had also received the Quidditch captain's badge and Head Girl badge respectively. Headmistress Minerva McGonagall had added a personal letter to Harry and Ron. She explained that she considered them both for Head Boy, but unlike Hermione she felt less certain if either of them would return for their NEWT year. In the end Ron had decided to join George rebuilding Weasleys' Wizarding Wheezes apart from his work for the Ministry. Harry had been convinced by Kingsley to work for the Ministry. Officially he held a position as a junior employee at the Department of Magical Law Enforcement. In reality he was leading the cooperation with the Muggle Americans and SG-M. With Hermione and Ginny at Hogwarts Harry and Ron slowly found a routine. They both lived at the Burrow and worked in London. Every weekend they met with their girlfriends in Hogsmeade. Hermione had an agreement with professor McGonagall that she would join Harry and Ron if SG-M was called into action. They hadn't given up on Gawain.

This particular day Harry was called to SGC and it was some time after lunch he was transported to Cheyenne Mountain.

"Good morning Harry." Jack greeted him with a yawn, holding a cup of coffee.

"Right, it's morning here." Harry replied "Good morning Jack, what's up?"

"You're asking me that?" Jack asked "All I know is that Doc Frasier got a delivery last evening from Pegasus and has been here all night, asked me to get you here and call to a meeting. We're going to the infirmary where SG-1 and Hammond are waiting."

Jack and Harry entered the infirmary where Dr Frasier stood next to a dead Wraith.

"Welcome Harry." general Hammond said and turned to Dr Frasier "Doctor, if you please. Why are we here?"

"I got this dead Wraith from Atlantis, because Dr Beckett wanted someone with more experience of researching magic to take a look." Dr Frasier began "And I'm fairly certain this Wraith was killed by magic."

"Gawain?" Harry asked with a renewed hope that they'd bring him back.

"There's a total lack of injury, no poison, pathogens or anything else that explains why he's dead." Dr Frasier continued.

Harry nodded, recognising the description.

"The Killing curse then." he concluded.

Dr Frasier agreed.

"That's my conclusion, since that's the only thing we know of that kills without leaving any clue. I still don't fully understand the Killing curse, but somehow negative emotions like hate or anger along with the incantation and wand movement produces a burst of _anti-life_, lacking a better word." Dr Frasier said "Any contact with a living organism causes the anti-life and life to erase each other without and trace of either left. But we also know that an unconditional love, such as Harry's mother displayed by sacrificing her life protected Harry. I have no idea how this protection works, or if it's possible to develop into a defence, that won't require the sacrifice of one life to save another."

"What about our fellow here then?" Jack asked interrupting the lecture.

Dr Frasier turned to general Hammond.

"Shepperd's team came across a hive, dead in space, and it wasn't the one that attacked Atlantis. This fellow comes from that hive."

"So Gawain escaped and is still out there somewhere?" Harry asked.

"The thing is that our Wraith here wasn't the only one. In fact every Wraith on the hive was dead. What's more, the organic-based systems on the hive were also, lacking a better word, dead." general Hammond explained.

Harry gasped.

"Are you saying an entire hive was AKd?" he asked.

"That's what we think." Dr Frasier said.

"But it's not possible." Harry said "Not even a Dark Wizard as powerful as Voldemort would be able to cast thousands of Killing curses in such a short time."

"Why is that?" Dr Frasier asked.

"Casting spells is exhausting. Just like physical activity strains the body, magic strains our core. Too much and too powerful magic in a short time will exhaust us." Harry explained "We can do normal magic all day, but extremely powerful spells like the Killing curse would exhaust any wizard."

"Nevertheless we have a hive with crew that seems to have been collectively AKd." general Hammond concluded "I'd like SG-M and SG-1 working with Shepperds team in order to find out what happened, and if possible rescue Gawain."

"Should I ask for a replacement for Gawain, or will it be me, Ron and Hermione?" Harry asked.

"Until we know Gawain's fate we don't replace him." general Hammond decided.

"One more question general." Harry said "Have the Unspeakables made any progress on the magic imbued in Atlantis?"

General Hammond nodded.

"They have uncovered several city wide charms. In fact I'd like to send a request with you to Kingsley, asking for an Unspeakable permanently assigned to Atlantis. The magic will greatly strengthen the defensive capability of the city." he said "Anything else?"

They all shook their heads.

"Dismissed." general Hammond said and approached Harry "If you'll come to my office before you leave I'll give you the request to Kingsley."

Harry and general Hammond left together.

"This is the first sign of anything magically related, suggesting Gawain is still alive, but I'm still not entirely happy about the news." Harry said.

"I know." general Hammond agreed "And since you say that one wizard couldn't have caused this it must be investigated. The Killing curse is one of the worst weapons I've ever heard of, and we are defenceless against it. Evidently the Wraith hive was defenceless too. The only good piece of news is that you're living proof of the fact that it is possible to be hit and survive."

Harry nodded in agreement.

"And the bad news is that we have absolutely no idea how we develop a defence." Harry added.

General Hammond only sighed, as he opened his door. After accepting an envelope Harry returned to the transportation site, to deliver it before he headed to Diagon Alley where Ron should be.

It was late in the afternoon and the shops in Diagon Alley prepared to close for the day when Harry entered Weaselys' Wizarding Wheezes. Ron, George and Verity were there tending to the last customers of the day.

"Harry my friend. How's the Ministry today?" Ron asked.

"Harassed by memos as usual, and that syrupy bint in the lift is as polite as ever." Harry grinned.

Ron shook his head.

"Honestly Harry, you should've accepted only part time in that place like me. I actually have fun working here, which makes the Ministry bearable."

"Yes, really Harry. If you'd work in the Hogsmeade shop you'd be closer to Ginny, and everyone would go there to buy Harry Potter's favourite pranks." George added.

Harry really disliked the hero status he'd been given after defeating Voldemort, which George knew very well.

"Prat." Harry replied.

"And proud." George countered with a grin "Ron, Verity and I can close up for the day. You go with Harry."

"Thanks bro'" Ron said.

The two friends left the shop.

"We need to talk." Harry said "Let's go home."

They turned and Disapparated with a soft pop. Outside the Burrow's wards they Apparated and walked the short distance to the house. They could smell Molly's supper from the garden.

"Hello Mum." Ron greeted "What's for supper?"

"Just a simple pie." Molly said.

"It smells delicious." Harry added.

"It'll be ready when Arthur comes home in about half an hour." Molly told them.

"All right, we'll be upstairs." Harry said and headed up to Ron's room.

Once inside Harry told Ron about the day.

"But after leaving the SGC I got an idea.." Harry said "I think Doc Frasier should examine me and Ginny."

Ron looked dubiously at Harry.

"Why?" he asked.

"Because I gave my life for her when I took the Killing curse Voldemort cast on me."

"And you survived because your mother's protection still was active after Voldemort took your blood."

"That is true, but the fact remains. Ginny is the only one who's been protected against the AK where the one willing to sacrifice his life survived. And that's what we want, a defence not claiming anyone's life."

Ron wasn't keen on the idea to involve his little sister in their work for SGC. She did know they worked with American Muggle military and had met SG-1 when they'd visited the Burrow, but she had no idea about the Stargate.

"And with Voldemort gone that protection is gone." Ron argued.

"True, but let's face the facts Ron. Something out there AKd an entire hive. I know an examination of Ginny and me might not reveal anything, but there is still a chance, and I think we must take it."

Ron nodded reluctantly, since Harry made a good point.

"But she's not going with us to Pegasus." Ron said.

"I don't want to put Ginny in any kind of danger, you know that." Harry said "But she's also of age."

"I'll support the idea to bring her to Doc Frasier." Ron said "Let's clear this with Kingsley first thing tomorrow, before we leave for SGC.

"I guess we need to tell Hermione today, and alert Ginny." Harry said.

Ron smiled at the thought of a quick visit at Hogwarts.

"We'll have time to Floo there and be back in time for supper." Ron decided and hurried downstairs.

Molly was setting the table and looked inquisitively at them when they headed for the fire place.

"We'll be back for supper Mum." Ron promised and tossed Floo Powder into the fire. "Minerva McGonagall's office."

A few moments later the headmistress had cleared them to Floo to her office.

"Good evening Harry and Ron." professor McGonagall greeted them as they stepped out of the Floo.

"Good evening professor." they replied.

"Goodness. It's Minerva. I'm not your professor any longer." she said "What can I do for you?"

"We need to bring Hermione along with us tomorrow, and provided Kingsley approves of it, we need Ginny too."

"Ginny? What for?" professor McGonagall asked.

Harry explained that there was a chance to maybe learn something about the Killing curse and come one step closer to a defence against it.

"Of course she can go, but don't make a habit out of it." the professor said.

Professor McGonagall didn't know exactly what kind of work they did, but Kingsley had explained that it was very important and if they requested her assistance it would be appreciated if she'd be willing to give it. Harry and Ron nodded and left her office to catch Hermione and Ginny in the Great Hall before supper was over. They quickly located the two witches sitting together at the Gryffindor table.

"Ginny" Harry said softly as he approached her.

She turned around with a smile on her lips.

"Harry, what are you doing here?" Ginny asked and gave him a hug and a quick kiss.

Hermione welcomed Ron in a similar way.

"We need you tomorrow 'Mione." Ron said.

Hermione simply nodded. She understood what it was all about and the professors would assist her to catch up with the lessons she missed.

"And we need you too Ginny." Harry added.

"Me?" she asked.

"We can't tell you too much here, but it involves our _colleagues_." Harry said, which clarified that it had to do with the American Muggles.

"All right." Ginny said.

"We'll clear everything with Kingsley tomorrow morning and send you a Patronus." Ron said.

"I can take morning classes then?" Hermione asked hopefully.

"Yes, you can." Ron confirmed.

"I wish we could stay, but Molly is about to finish supper, so we better get back home." Harry said.

After a few more kisses Harry and Ron left Hogwarts and headed for the Burrow and supper.

Ginny was looking around the corridors of SCG. She had been cleared to participate in the research concerning the Killing curse and would report to the infirmary along with Harry. Researching the Killing curse seemed more important than ever since it seemed an entire hive had fallen victim to it. "Harry, when are you going to tell me exactly what you need my help with." Ginny asked.

Harry smiled.

"First of all, this place needs something pretty around." Harry said.

"Tosspot." Ginny huffed "But thank you."

"All right, really. We're going to the infirmary to see Dr Frasier, who's the equivalent of Madame Pomfrey around here." Harry said "And she's researching the Killing curse, and if there's a way to defend against it."

"And she's a Muggle?" Ginny asked for clarification.

"Ginny, these aren't your average Muggles. So far we've learned a lot from this cooperation, even the Unspeakables are making sense after being here." Hermione said.

Ron opened a door and invited them to enter.

"Well, here we are."

Once inside Dr Frasier and Sam greeted them, especially Ginny.

"So you're Harry's Ginny." Dr Frasier asked.

"She's also my sister." Ron added.

"Yes Dr Frasier, I'm Harry's girlfriend." Ginny confirmed, ignoring Ron's grimace.

Dr Frasier looked at the two of them. It was hard to believe what they'd been though in the Wizarding war, which she had been fully briefed on in order to better understand the circumstances allowing Harry to survive the Killing curse.

"Ginny, Sam and I will examine you and Harry and take every conceivable reading we can think of. If there's anything left of the protection Harry's sacrifice created, despite Voldemort is dead we hope to find it and try to understand what it is." Dr Frasier explained.

Ginny nodded.

An hour later Ginny and Harry had submitted to MRI and CT scanning, blood samples and a whole battery of tests.

"There it is, do you see it Janet?" Sam asked.

"Are you sure it's not a glitch?" Dr Frasier replied.

"I don't think the same glitch would occur in both Harry and Ginny at the same time." Sam reasoned.

The two of them continued to debate something obviously significant, but Harry and Ginny didn't understand a word of it..

"I think we need to gather the team in the briefing room." Sam decided and called general Hammond.

Ten minutes later SG-1, SG-M (along with Ginny) and Dr Frasier where gathered in the briefing room.

"Doctor, if you please." general Hammond said.

Dr Frasier displayed a set of images.

"As you know we have examined both Harry and Ginny, since they both have been protected from the Killing curse through the ancient blood magic that saved Harry's life as a baby. We didn't expect to find anything conclusive this fast but we think we have made an important discovery." Dr Frasier said and turned to Sam.

"If you look at this first image it's a faint pattern we found in the same part of both Harry's and Ginny's brains. We have examined Harry before, but obviously missed it. It's easy to dismiss as a glitch, but not when it shows up in a very precise part of the brain in two different people." Sam explained "Janet's or my brains don't show this pattern. Now look at this pattern."

Sam displayed a second image.

"That's from Telchak's healing device, that I dug up this summer." Daniel said and looked at SG-M "I haven't had time to tell you about that one."

"Exactly" Dr Frasier said "Can you see the similarity between the patterns?"

They all nodded.

"As I said earlier, we think the Killing curse is a burst of anti-life, and if it gets any contact with life both are erased without a trace. We know that it takes strong hatred to cast it, along with the incantation and correct wand movement. We know that an unconditional love and willingness to sacrifice one's own life can protect another person. What we haven't had any clue to is how this all works." Sam lectured.

"But now you have a theory." general Hammond asked.

"Not so much of a theory just yet," Sam continued "Janet, can you explain."

"Telchak's device had the power to animate dead tissue, and with research we could also develop the gun we use to kill the still roaming Kull warriors, without depending on our wizarding friends to AK them."

"You've cast the Killing curse?" Ginny whispered in Harry's ear.

"Only on some really scary Muggle versions of Inferi, nothing else worked." Harry replied.

"The fact that Harry and Ginny show this pattern, although faint, is an indication that it's the kind of energy that protects against the Killing Curse."

"And we hope that Telchak's device might be possible to use to develop a defence against the Killing Curse."

"How?" general Hammond asked.

"We don't really know yet." Sam replied "But maybe we can create some kind of shield, a life force shield if you will. And if a Killing curse hits it _kills_ the life force in the shield instead of the intended target."

"That's bloody brilliant." Ron said.

"I couldn't agree more." Jack said.

"Calm down." Dr Frasier said "This is not even a sound theory yet. We need time to research this, develop a force field with this kind of energy and test it. One thing we haven't a clue about is how the blood relates to this. How did the taking of Harry's blood keep the protection alive? But we'll analyse the blood samples."

Daniel looked at Dr Frasier.

"I don't have an answer, but in many ancient cultures blood is the symbol of life. Maybe there's more truth to that than we think."

Dr Frasier nodded.

"Possibly there's some kind of magical aspect we still have to understand." Hermione added. "In Harry's case the protection lived on through his aunt in the first place and she was nowhere near Godric's Hollow when Harry's mum sacrificed her love."

"As long as there's a chance we can defend ourselves Harry's aunt can be precisely where she likes." Jack meant.

"As long as it's not where we are." Harry added with a huff.

"I want all of you on your way to Atlantis." general Hammond ordered "Where research will continue along with reconnaissance missions to learn more about the dead hive."

Ginny looked at Harry.

"Atlantis?" she asked.

"It's a long story." Harry said.

"I thought we agreed Ginny wasn't going." Ron said.

"You said you didn't want her to." Harry replied "I said she's a witch of age."

Ginny loved that Harry finally had realised she was perfectly capable of making up her own mind, although his wish to keep her safe was rather flattering too.

"While our boyfriends work out their protectiveness of us, I'll tell you all about Atlantis." Hermione said.

A couple of hours later SG-1, SG-M, Ginny and Dr Frasier stepped through the Stargate for Atlantis. On the other side they were welcomed by a couple of familiar faces. Colonel Shepperd, Dr Weir, Teyla, Rodney and a rather big fellow were there to greet them.

"Welcome back to Atlantis" Dr Weir said "And this time we're not under attack."

"If we had time we could give you the grand tour, but we have work to do." John added.

"Dr Frasier, your first mission here, Dr Beckett will be glad to have you here" Dr Weir continued and her eyes fell on Ginny "I'm Dr Elizabeth Weir and I command this expedition."

"Ginny Weasley, Harry's girlfriend and Ron's sister." Ginny said "I was protected from the Killing curse when Harry was hit, so Dr Frasier is trying to figure out how that happened."

"John Shepperd, ranking military office of this expedition." John greeted her "And my team, Teyla Emmagan, Dr Rodney McKay and Ronon Dex."

After a round of handshakes Dr Weir called for attention.

"All right, you'll be shown to your quarters first. Then I want the research team set up immediately, and that's Dr Frasier, Dr McKay, Lt Col Carter, Miss Weasley and Mr Potter. Dr Beckett will assist if necessary" she ordered "Reconnaissance team, meaning the rest of you, report to the briefing room. We have some clues to work on."

As they left Jack approached John.

"Who's your new team member?" he asked and nodded to Ronon.

"He's a former runner." John said "I guess it's a kind of Wraith sport. They put a transmitter inside you, giving away your position, then they hunt you. Just for fun."

"Didn't their mum's teach them not to play with their food?" Jack asked.

"Apparently not." John shrugged "Ronon survived for years, but he doesn't talk much about it. But he's a magnificent warrior and he wants to fight the Wraith."

Hermione and Ginny got a room to share, next to Harry and Ron. The four of them left their quarters together.

"So, I guess Harry and I are stuck here, while you go off on some dangerous mission." Ginny said.

"Ginny, it's only a reconnaissance mission." Ron argued.

"Actually, I'd rather stay with Sam and Janet." Hermione said and looked at Ginny "They're really great. And this is Merlin's city. Imagine the knowledge the libraries here must contain."

"Bloody hell 'Mione, you're in another galaxy and you're thinking about reading."

"And you're probably already thinking about the local food you hope to try out." Hermione replied with a snort.

Harry chuckled.

"Ginny, I'm rather pleased that I won't be the one sent off on some dodgy mission. And I get to be with you."

"I know Harry. It's just that the last time I was left behind, to be kept safe, I ended up fighting the Death Eaters at Hogwarts all year." Ginny said.

"This city is probably safer that Hogwarts, the Unspeakables have seen to that." Hermione said.

They soon parted as Harry and Ginny headed for the lag, while Ron and Hermione continued to the briefing room.

The briefing was rather formal gathering. It turned out that one of Teyla's contacts had sent a message. The contact wanted to meet and share information about the dead hive.

"I don't have to tell you to be careful." Dr Weir finished.

"Gear up then. We leave in 20 minutes." Shepperd said.

"Are you sure we should bring the children?" Ronon asked nodding to Ron and Hermione.

Shepperd had realised that Ronon would raise this objection and was prepared for it.

"Hermione. Would you be kind enough to fight with Ronon, but please make sure he'll be fit to join us on the mission?" Shepperd asked.

Ronon looked dubiously at Shepperd.

"I don't want to hurt her." he said.

"You won't" Jack said, supporting John "Trust me."

"Indeed." Teal'c added, who had learned the hard way, in friendly fights against Gawain, that fighting a wizard or witch wasn't easy.

Ronon, several inches taller than Ron, got up and assumed a fighting stance. Hermione stood up and faced him with her wand in her hand.

"Are you sure about this John?" Dr Weir asked.

"Yes, it's the only way they will earn Ronon's respect." John said and looked at the two "Begin."

Ronon attacked.

"Accio gun. Levicorpus." Hermione said and hoisted Ronon up in the air as she caught his gun.

"Our wizarding friends are so cool." Jack said with a smile.

"Is this enough?" Hermione asked looking at John.

"Actually, I haven't seen all the neat things Jack is bragging about." he replied "Please continue."

Hermione shrugged and made a demonstration on the helpless Ronon. She transfigured him into a rabbit and back, hit him with a tickling hex, released him to the floor and cast a jelly-leg jinx as soon as he tried to stand up. Ronon fell to the floor howling with laughter. After this Hermione released him.

"And that was only some basic transfiguration and prank hexes." Hermione told him.

Ronon darkened for a few moments, as if he considered attacking her again. But he realised he wasn't made fun of. This youngster was indeed a warrior worthy of his respect.

"I'm glad you're on our side." he said and relaxed "I'll be honoured to fight next to you."

"That's settled then." Dr Weir smirked "Now, get ready."

At the designated time the team moved out. Teyla, Teal'c and Ronon taking the lead, followed by Ron and Hermione, with Jack and John after them. Emerging on the other side of the wormhole Teyla met her contact who was waiting for them.

"This is Ina'an." he'll take us to his home, where his source is waiting. It's about 30 minutes to walk" she told.

"Lead the way." John said.

They walked on a road with fields on both sides and the sun shone from a blue sky. A nearby gas giant was also visible despite it was day.

"It's almost like Devon." Ron noted.

"Well Dorothy, it sure as hell isn't Kansas." Jack told Ron, pointing at the gas giant.

"But we do have a witch present." Hermione grinned, continuing the reference to the Wizard of Oz "But I don't consider myself wicked."

They kept walking towards a farm, feeling rather relaxed. Once at the farm Ina'an invited them into his parlour.

"I'll just bring the people you're here to see. They're in the next room." Ina'an said.

He opened the door and a Wraith entered. Everyone had their weapons, and in Ron's and Hermione's case wands, ready in a flash.

"Please don't shoot." Ina'an pleaded "I haven't betrayed you. Please listen to them."

Teyla hesitated. She'd known Ina'an for many seasons and knew he was an honourable man.

"Let's listen to them." Teyla said.

Shepperd nodded. If the Wraith had wanted to capture them they'd try to cull them out in the open, rather than risking their own life like this.

"Speak Wraith." Shepperd urged, not lowering his gun.

"We need your help." the Wraith began.


End file.
